Science and conservation for the world’s 2800 small mammal species

Top 20 ‘Lost’ Small Mammals

Red Crested Tree Rat Santamartamys rufodorsalis (courtesy of Lizzie Noble)

Red Crested Tree Rat Santamartamys rufodorsalis was ‘lost’ for 113 years (image courtesy of Lizzie Noble)

As a group, small mammals are very poorly known.  And many species have been ‘lost’ to science. In other words, these are species that haven’t been observed by scientists for many years – and in some remote areas of the world, some species haven’t been recorded for over 100 years.  Have they gone extinct or have we not looked hard enough?  The red-crested tree rat Santamartamys rufodorsalis provides a clue to answering this question. Originally described in 1898 when two specimens were collected from the Santa Marta Mountains in Colombia, the species wasn’t seen again until 2011 when one was seen shuffling along a walkway handrail in the El Dorado Nature Reserve – that’s 113 years of being ‘lost’.

Here is our list of the Top 20 ‘Lost’ small mammals – surveys are urgently needed for these species to establish whether they are still alive today and, if so, to determine their status and conservation needs. For more information, click on each species to take you to the relevant account on the IUCN Red List of Threatened Species.

 

1. Namdapha flying squirrel (Biswamoyopterus biswasi)

Order: Rodentia

Red List status: CR

Endemic to: India

Lost since: 1981

2. Zuniga’s dark rice rat (Melanomys zunigae)

Order:  Rodentia

Red List status:  CR (PE)

Endemic to: Peru

Lost since:  1949

3. Wimmer’s shrew (Crocidura wimmeri)

Order: Eulipotyphla

Red List status: CR (PE)

Endemic to: Côte d’Ivoire

Lost since: 1976

4. Vernay’s climbing mouse (Dendromus vernayi)

Order: Rodentia

Red List status: DD

Endemic to: Angola

Lost since: 1937

5. Shortridge’s rat (Thallomys shortridgei)

Order: Rodentia

Red List status: DD

Endemic to: South Africa

Lost since: 1922

6. San Quintin kangaroo rat (Dipodomys gravipes)

Order: Rodentia

Red List status: CR (PE)

Endemic to: Mexico

Lost since: 1986

7. Puebla deer mouse (Peromyscus mekisturus)

Order: Rodentia

Red List status: CR (PE)

Endemic to: Mexico

Lost since: 1948

8. Manusela mosaic-tailed rat (Melomys fraterculus)

Order: Rodentia

Red List status: CR

Endemic to: Indonesia

Lost since: 1920

9. Lesser stick-nest rat (Leporillus apicalis)

Order: Rodentia

Red List status: CR (PE)

Endemic to: Australia

Lost since: 1933

10. Isla Mocha degu (Octodon pacificus)

Order: Rodentia

Red List status: CR

Endemic to: Chile

Lost since: 1959

11. Isla De La Juventud tree hutia (Mysateles meridionalis)

Order: Rodentia

Red List status: CR

Endemic to: Cuba

Lost since: 1978

12. Ilin bushy-tailed cloud rat (Crateromys paulus)

Order: Rodentia

Red List status: DD

Endemic to: Philippines

Lost since: 1953

13. Guadalcanal rat (Uromys porculus)

Order: Rodentia

Red List status: CR (PE)

Endemic to: Solomon Islands

Lost since: 1888

14. Groove-toothed forest mouse (Leimacomys buettneri)

Order: Rodentia

Red List status: DD

Endemic to: Togo (Close to Ghana border)

Lost since: 1890

15. Emperor rat (Uromys imperator)

Order: Rodentia

Red List status: CR (PE)

Endemic to: Solomon Islands

Lost since: 1887

16. Emma’s giant rat (Uromys emmae)

Order: Rodentia

Red List status: CR (PE)

Endemic to: Indonesia

Lost since: 1946

17. Eisentraut’s mouse shrew (Myosorex eisentrauti)

Order: Eulipotyphla

Red List status: CR

Endemic to: Equatorial Guinea (Bioko Island)

Lost since: 1968

18. Christmas Island shrew (Crocidura trichura)

Order: Eulipotyphla

Red List status: CR (PE)

Endemic to: Australia (Christmas Island)

Lost since: 1985

19. Angel Island mouse (Peromyscus guardia)

Order: Rodentia

Red List status: CR (PE)

Endemic to: Mexico (Ángel de la Guarda Island)

Lost since: 1991

20. Alcorn’s pocket gopher (Pappogeomys alcorni)

Order: Rodentia

Red List status: CR

Endemic to: Mexcio

Lost since: 1998